Everyone knows you can do SELECT SYSDATE FROM DUAL to get a single row representing today's date.
I'd like to do something similar, but it would look like:
SELECT MAGICDATE FROM DUAL
WHERE MAGICDATE = Prompted in the application software
Bit of a long story why...
I'm using a package called SAP Business Objects. It translates user queries into SQL and can get a little tricky. I would like to pull out the user prompts into separate little sub-queries, then use the results of the prompts to power my main queries.
The queries look like:
select user_id, test_centre, test_date, count(*)
from
Lots of tables
where user_id in Prompted User Id
and test_centre in Prompted test_centre
and test_date between Prompted Date 1 and Prompted Date 2
Here's one way of doing it:
SELECT TRUNC(SYSDATE) + dbms_random.value(-5000, 5000) random_date,
TRUNC(SYSDATE) + floor(dbms_random.value(-5000, 5000)) random_datetime
FROM dual;
I've provided ways to get both a random date and a random date + time. Note that I've used TRUNC(SYSDATE) as the seed date and range of 5000 days before and after. You may wish to change the seed date so that it's SYSDATE or even a fixed date, as well as to amend the date ranges as per your requirements.
Can you just do this?
select to_date([prompted_date],'someformat') from dual
The actual answer to your question is:
select #prompt(.....) from dual
But I don't think that is actually what you're looking for. Can you be more specific about what you are attempting to do?
Related
I have a need to pull in via FTP only files from dates I haven't pulled data. The data pulls happen nightly, but occasionally there is an issue and a night gets skipped, and it will be picked up the following night.
I located a query on StackOverflow which addressed most of my problem. However, I'm left with an uncomfortable solution and a lingering question.
I have a table with data from each file downloaded. The crux of the data I'm using for this example is EXTRACT_DATE. The file format is filename_20160809.csv, as an example. Uses the 4-digit year, 2-digit month and 2-digit day to make unique. The FTP location has thousands of files, and I only want to grab the new, based on this date.
First, I get the latest EXTRACT_DATE from my table as such
SELECT MAX(EXTRACT_DATE) INTO checkDate FROM FILE_DETAILS;
I had attempted to do this in a single query, but couldn't work it, and finally attempted to create a variable, checkDate, and use this variable in a subsequent query to obtain my list. However, having two queries in a single script is not allowed, or I haven't found a way to do it. So my primary issue is to return the value of the latest date. Then call a new query or procedure with the value incorporated in to obtain my list, with this query
SELECT TO_DATE(checkDate, 'MM/DD/YYYY') + rownum AS EXTRACT_DATES
FROM ALL_OBJECTS
WHERE TO_DATE(checkDate, 'MM/DD/YYYY') + rownum <= TO_DATE(SYSDATE, 'DD-MM-YY');
This solution is messy and uncomfortable, I would prefer a single query to get back my results, rather then 2 scripts or a script and a procedure.
The lingering question, the result from the query returns dates in the mm/dd/yyyy format; 8/9/2016. I adjusted the TO_DATE to match.
Initially, it was set to return as YYYY-MM-DD; 2016-08-09.
However, it wouldn't return in this format. It would only come back as 8/9/2016, regardless of the TO_DATE formatting used. I don't understand why the date is coming back in this format.
SELECT TO_DATE('2-AUG-2016', 'DD-MON-RR') + rownum AS EXTRACT_DATES
FROM ALL_OBJECTS
WHERE TO_DATE('2-AUG-2016', 'DD-MON-RR') + rownum <= TO_DATE(SYSDATE, 'DD-MM-YY');
EXTRACT_DATES
8/3/2016
8/4/2016
8/5/2016
8/6/2016
8/7/2016
8/8/2016
8/9/2016
NLS_DATE_FORMAT is set to DD-MON-RR, with American as NLS_DATE_LANGUAGE.
Am at the end of my tether so hoping someone can help me! I'm really new to Oracle, but do have a SQL background which is why I'm finding this so frustrating!
We have a system that runs Oracle at the back end. I've got very limited access to the system and can only write select queries.
I've written a query that gets the data I want but the date format is coming out as mm dd yyyy what I need is dd/mm/yyyy
I ran SELECT sysdate FROM dual and that come back as:
SYSDATE
03 11 2015
So my select statement reads (action_date is the column in question)
Select username, action_date from adminview
I've tried everything I can think of to change the date format including:
to_date(action_date,'dd/mm/yyyy')
to_date(action_date,'dd/mm/yyyy','nls_language=English')
to_date(to_date(action_date,'mm dd yyyy'),'dd/mm/yyyy')
I've also tried to_char along the same lines.
If you want to format a DATE value, use TO_CHAR():
SELECT username, TO_CHAR(action_date, 'DD/MM/YYYY') AS action_date
FROM adminview;
If it's not a DATE value, then you'll want to convert it to a DATE (based on what it currently looks like), then use TO_CHAR() to format.
I have a timestamp column in a monetdb table which I want to occasionally group by hour and occasionally group by day or month. What is the most optimal way of doing this in MonetDB?
In say postgres you could do something like:
select date_trunc('day', order_time), count(*)
from orders
group by date_trunc('day', order_time);
Which I appreciate would not use an index, but is there any way of doing this in MonetDB without creating additional date columns holding day, month and year truncated values?
Thanks.
You could use the EXTRACT(DAY FROM order_time) possibly as part of a subquery before grouping.
It might be a little late for answer, but the following should work for truncating to day precision:
SELECT CAST(order_time AS DATE) AS order_date, count(*)
FROM orders
GROUP BY order_date;
It works by casting the timestamp value to type DATE which is a MonetDB built-in type and the cast is pretty fast.
It does not have the flexibility of date_trunc in Postgres, but if you need to go to monthly of yearly precision, you could use the somewhat slower but usable EXTRACT to get the relevant parts of the timestamp and group by them. For monthly grouping, you could do:
SELECT EXTRACT(YEAR FROM order_time) AS y,
EXTRACT(MONTH FROM order_time) AS m,
count(*)
FROM orders GROUP BY y, m;
The only disadvantage is that you will have the date split to two columns.
I need to retrieve using an oracle based query the working time of an employee which is the time coming in and time going out for an employee based on his transactions in the transaction table.
The transaction table has a date-time field which can be used for this purpose.
The steps involved would be as follows:
1) find the first transaction on a date and the last transaction on the same date - that would be his time in and timeout for that date
2) calculate the overall time-in as the avg of all time-ins on each date, similarly do for time-out
Transaction table is as follows: transctn(transid, resourceid, event, currentdate)
The second requirement is to find the average transactions performed each day, which is basically find the count of transids for each day and then average of that.
The final answer should be, when a userid is provided the query the return result is:
frequent working time(based on average): 9:43 am - 6:45 pm
average transactions performed/day = 43
How do I write the above requirement in oracle SQL or more smartly using Hibernate if Transctn is my Domain class
I have something like this:
select 'frequent working time: '
||(select rtrim(to_char(min(currentdate),'hh:mi pm')) from transctn)
||' - '||(select rtrim(to_char(max(currentdate),'hh:mi pm')) from transctn)
||', average transactions performed/day = '
||(select rtrim(to_char(count(distinct transid)/
count(distinct(to_char(currentdate,'rrmmdd')))) from transctn)
from dual
Firstly, your query has lots of selects from the same table stuck together, which isn't efficient, and makes it harder to read than necessary. And the rtrim isn't doing anything as you've already dictated the format. What you have can be rewritten as:
select 'frequent working time: '|| to_char(min(currentdate),'hh:mi pm')
||' - '|| to_char(max(currentdate),'hh:mi pm'),
'average transactions performed/day = '
|| to_char(count(distinct transid)
/count(distinct to_char(currentdate,'rrmmdd')))
from transctn;
But this isn't averaging properly, and isn't for a specific user. I'm join to assume this is homework and in the usual spirit of the site, try to give you pointers rather than the complete answer...
1) find the first transaction on a date and the last transaction on
the same date - that would be his time in and timeout for that date
You're not far off here, but you're breaking down by date. To get the time-in and time-out for every user, for each day, you could use:
select resourceid, trunc(currentdate), min(currentdate), max(currentdate)
from transctn
group by resourceid, trunc(currentdate)
order by resourceid, trunc(currentdate);
2) calculate the overall time-in as the avg of all time-ins on each
date, similarly do for time-out
You can't average dates directly in Oracle; you'd get ORA-00932: inconsistent datatypes: expected NUMBER got DATE. There are various ways to achieve the effect, you just need to figure out a safe way to treat the date - or more specifically here the time part - as a number. For example, you could treat the time portion as the difference between the actual time and the start of the day, which Oracle returns as a number:
select avg(min(currentdate) - trunc(currentdate)),
avg(max(currentdate) - trunc(currentdate))
from transctn
group by trunc(currentdate);
But you than have to translate that fractional number back into something recognisable. One way of doing that is to add the number to an arbitrary fixed date, and then just extract the time part as a string as you were already doing:
select to_char(date '2000-01-01' + avg(min(currentdate) - trunc(currentdate)),
'HH:MI pm') as avg_time_in,
to_char(date '2000-01-01' + avg(max(currentdate) - trunc(currentdate)),
'HH:MI pm') as avg_time_out
from transctn
group by trunc(currentdate);
This look messy and you might find a better way to do it. If it is homework then I would assume you've been taught methods for doing this sort of thing, or something that can be adapted to be applicable.
This is still for all resources, so you'll need to add a filter to restrict to one user ID. Hopefully this gives you some ideas for tackling the second requirement as well.
Ok, I'm new using this connect by thing. But its always quite useful. I have this small problem you guys might be able to help me...
Given start month (say to_char(sysdate,'YYYYMM')) and end month (say, to_char(add_months(sysdate, 6),'YYYYMM')), want to get the list of months in between, in the same format.
Well, I want to use this into a partitions automation script. My best shot so far (pretty pitiful) yields invalid months e.g.'201034'... (and yea, I know, incredibly inefficient)
Follows the code:
SELECT id
from
(select to_char(add_months(sysdate, 6),'YYYYMM') as tn_end, to_char(sysdate,'YYYYMM') as tn_start from dual) tabla,
(select * from
(Select Level as Id from dual connect by Level <= (Select to_char(add_months(sysdate, 1),'YYYYMM')from dual)) where id > to_char(sysdate,'YYYYMM')) t
Where
t.Id between tabla.tn_start and tabla.tn_end
how do I do to make this query return only valid months? Any tips?
cheers mates,
f.
Best way might be to separate out the row generator from the date function. So generate a list from 0 to 6 and calculate months from that. If you want to pass the months in then do that in the with clause
with my_counter as (
Select Level-1 as id
from dual
connect by Level <= 7
)
select to_char(add_months(sysdate, id),'YYYYMM') from my_counter
The example below will allow you to plug in the dates you require to work out the difference.
with my_counter as (
Select Level-1 as id
from dual
connect by level <= months_between(add_months(trunc(sysdate,'MM'), 6),
trunc(sysdate,'MM')) + 1
)
select to_char(add_months(trunc(sysdate, 'MM'), id),'YYYYMM') from my_counter
For generating dates and date ranges, I strongly suggest you create a permanent calendar table with one row for each day. Even if you keep 20 years in this table it will be small ~7500 rows. Having such a table lets you attach additional (potentially non-standard) information to a date. For example your company may use a 6-week reporting period which you cannot extract using TO_CHAR / TO_DATE. Pre-compute it and store it in this table.
Oh, and Oracle 11g has automatic partition management. If you are stuck with 10g, then this article may be of interest to you? Automatic Partition Management for Oracle 10g
Try this:
with numbers as
( select level as n from dual
connect by level <= 7
)
select to_char (add_months (trunc(sysdate,'MM'), n-1), 'YYYYMM') id
from numbers;
ID
------
201012
201101
201102
201103
201104
201105
201106